Brake mechanism



June 1?, 1941. H. T. LAMBERT 2,245,938

BRAKE MECHANISM Filed July 29, 1940 2 Sheet-Sheet 1 I flue W June 17, 1%41.

H. T. LAMBERT BRAKE MECHANISM 2 Sheets-Sheet 2 Filed July 29, 1940 L. g i

1 izing means of this invention, and

Patented June 17, 1941 UNlTED- STATES PATENT OFFICE BRAKE MECHANISM Homer T. Lambert, St. Joseph, Mich.

Application July 29,1940, Serial No. 348,254

6 Claims.

The present invention relates to improvements in brake mechanism designed particularly for use on motor vehicles. Specifically, the invention appertains to a novel 'parking or emergency brake more especially applicable to a disc type of brake construction.

It is well known that in anumber of States,

regulations require that in addition to the usual service or foot brake there shall be provided an independent emergency or parking brake, and it is the object of this invention to provide a simple and efiective manually operative arrangement complying fully with these requirements, for the type of brake referred to. p

It is further an object of this invention to provide a brake mechanism embodying in combina-- tion with a pressure plate,- a pair of insert discs having grooves or recesses and inclined surfaces to cooperate with interposed rolling members, by

. means of which axial pressure may be imparted to the pressure plate upon movement of one of said discs relatively to the other and independently of the main brake.

Other and further objects and advantages of the invention will be hereinafter. set forth and the novel features thereof defined by the appended claims.

In the accompanying drawings- Figure 1 is a .fragmentary vertical sectional view of a brake construction to which my present invention is applied;

Figure 2 is an enlarged vertical sectional view taken about on the plane indicated by the line 22 of Figure 1;

Figure 3 is an enlarged sectional view on the plane indicated by the line 3-3 of Figure 2.

Figures 4 to 7 are detail views of the disc and rolling members constituting the primary ener- Figures 8 and 9 are enlarged sectional views axle support for the wheel (not shown) in the manner disclosed in my copending application, Serial No. 322,027 flied March 2, 1940, and in which it is fully described and claimed, exclusive of the auxiliary emergency and parking brake of this application. For the purposes of the present disclosure, the construction will be briefly set forth herein.-

The drum housing I0 is threaded internally at 10' to receive the brake disc I2 which in turn is correspondingly threaded exteriorly for adjustment inwardly and outwardly of the drumhousing It). Y

Within the drum the rotary brake ring i 3 is mounted upon the inner-extensions 9' of the stud bolts 9, said ring carrying a friction lining or surfacematerial l4 at each side. The ring is formed with a series of bearing lugs I 5, each provided with an aperture to receive the extensions 9' serving to guide the ring and impart rotationthereto.

In order to facilitate the axial sliding movement of the ,ring, a metallic thimble bushing or spring ferrule IB is disposed in each opening of the driving lugs IS. The construction of this ferrule is clearly shown to comprise a split sleeve, normally tapered longitudinally and having a flange I6 at one end and spaced upset protuberances Ilia. at the other end. As the ferrules are introduced into the openings of the lugs l5, the spring metal sleeve is compressed until the walls assume a substantially parallel positiontending to hold the ring H! in a true vertical position and insure free self-adjusting sliding the adjacent parts during braking operation.

40 of the upper and lower parts respectively of the brake construction showing more clearly the de- 7 This particular form of bushing eliminates the necessity of employing yieldable rubber bushings which have a tendency to become inoperative and interfere to a certain extent with the free sliding movement of the brake ring.

Within the housing I 0 at the side 'of the ring I 3 opposite the brake disc I! is arranged a free floating pressure plate I! formed with the laterally 'extending annular flange I 8 extending into an annular recess l9 in the inner face of the drum housing.

Since the brake construction herein described is of the hydraulic type, the flange l8 constitutes a piston and the recess l9 its cylinder. A channeled sealing reinforced rubber ring l8 cooperates with the flange l8 and the pressure medium is admitted to the cylinder through the nipple 20 so as to actuat the pressure plate I! to move it axially until it contacts with the rotary brake ring l3, thereupon picking up rotation of the latter when the vehicle is moving and setting up servo action by instrumentalities now to be described.

As will be clearly seen by reference to Figure 8, the pressure plate H in one face is provided with a plurality of circular recesses 2| (one only appearing in this view, but preferably three of such recesses are formed) and in-each of these recesses is fixed a hardened steel insert 22 having a transverse substantially V-shaped groove 22' therein. Each of such inserts is faced with a substantially corresponding insert 23 rotatably mounted on the inner face of the drum housing II) by means of a centralizing boss 24 seating in a recess 25. This construction of insert I "have found desirable for those that are intended to rotate, as there is less tendency, for them to freeze or stick in their seats, and they produce less friction.

Between each pair of these discs is a roller 26 seating in the insert grooves. It will be understood that balls in conical recesses may be substituted for the roller arrangement illustrated, and, therefore, I do not wish to be restricted as regards the form of this energizer means.

Under normal conditions, the pressure plate I! is held away from the braking ring l3 by means of the tension springs 2'i, each of which is connected at one end to a lug 28 on the plate, and at its other end to a corresponding lug 29 formed on the housing it in opposed relation to the lug 28. Any number of these tensioning elements may be employed for the purpose stated. Itwlll also be obvious that spring arrangements of diflerent form may be employed and arranged to coact with the pressure plate to function in the same manner as the springs 2i, and, for this reason, I do not wish to be restricted to the particular type of tensioning means shown in the drawings.

As hereinbefore described, the brake disc i2 is ,screwed into the open end of the drum it to the proper position for cooperation with the braking ring it. This mounting of the brake disc enables adjustment of this element for clearance between the braking parts, and once the adjustment has been obtained, the position of the brake disc I? is maintained by a special locking feature which is now to be described. As shown clearly in Figure 3 of the drawings, the peripheral face of the drum housing it is notched to provide a series of locking teeth 3G extending completely about the drum edge. A locking plate 3| having at its free end teeth corresponding to the teeth 38 is secured by means of a bolt 32 passing through an aperture in its other end to the brake disc l2 having a threaded aperture therein to receive said bolt. In order to takeup wear of the braking parts and maintain a proper clearance adjustment between the same, the locking plate 3| is released from the engagement of its teeth-with those on the drum i0 by backing out the bolt 32. For this purpose, an implement in thenature of a socket-wrench 33 is introduced through an opening engaged with the head of the bolt 32. By taking hold of the wheelafter the bolt has been backed out sufficiently far to establish a clearance between the interengaging teeth, the brake disc I2 may be rotated inwardly or outwardly, as the case may be, by the turning action of the wheel itself. Thus, through the wrench or implement 33 aconnection is established between the wheel and the brake disc i2 to produce the 34 in the wheel and contact with the brake disc l2 and rotative movement, and due to the leverage which is provided by the wheel, the adjustment of the'brake disc in the manner described is greatly facilitated, and without the necessity of removing the wheel for such purpose. After the adjustment has been reached, the wrench is then operated to reengage the locking plate 3| and secure the same in a tightened position for preventing any further movement of the brake disc during the normal operation of the braking elements.

The operation of the service brake portion will be clear from the foregoing description, and it sufilces to say by way of summary that, when service brake application is to be obtained, the pressure medium is admitted to the brake unit through the conduit 35 to act against the piston flange l8 of the pressure plate Ii. The pressure moves the pressure plate intocontact with the friction surface of the rotating brake ring I3, and thereupon the rotatlve movement of this part is picked up by thepressure, plate. Slight rotary movement of the last-named plate causes the rollers 26 to climb up the cam faces of the insert elements 22 and 23 tothereby cause further axial movement of the pressure plate against the braking ring l3, which is axially moved also to provides the necessary braking action of the parts. Upon relief of the hydraulic pressure, the tension of the springs 21 pulls the pressure plate I! away from the braking ring [3 and normalizes the brake construction. This braking operation, by virtue of the construction of the self-energizing parts, may be obtained in either direction of movement of the vehicle. The simplicity of the construction the main hydraulic means,

and arrangement of the parts, the accessibility of the same, and the facility with which adjustment may be secured to take up wear are of prime importance in the advantages attributable to these particular brake improvements.

Now referring to the construction of the auxiliary brake features, shown most clearly in Figures 2 to 7, the pressure plate I1 is formed adjacent its periphery with a circular recess 36 in which is fixedly secured a disc 31 having a transverse groove 31' with oppositely inclined camming surfaces 36, all similar to the construction of the energizing discs or inserts 22 heretofore described.

A second disc 38 is rotatably mounted in opposed relation to its companion disc 31 in the drum housing in by means of its shank 39 which is of sufldcient length to project through the opening l0 and is formed with the squared terminus M. Upon said extremity is secured the lever arm 42, as by means of the bolt 43.

The inner face of the disc 38 is formed with a pair of conical recesses 38' providing seats for a pair of anti-friction balls 46 normally resting in in the disc insert 31.

A brake rod is connected to the lever 42 and leads to a manual brake lever (not shown) arranged convenient to th operator of the vehicle.

From the foregoing it will be understood that the pressure plate may be shifted, not only by for service application of the brake, but also independently by the auxiliary actuating means, in emergency or parking brake application as will now be set forth. For parking, after the vehicle has been stopped, the lever 42 is actuated by the brake lever, thereby causing the disc 38 to rotate and the ball members to ride upon the camming surfaces 36 of the disc 31, one ball up one surface and the other ball up the other surface. This action presses the plate l1 firmly against the rotary ring l3 and it in turn against the stationary brake member l2, locking the against movement.

In the event the hydraulic service brake should become inoperative for one reason or another, .while the vehicle is moving, the manual brake lever may be shifted as described above, resulting in contacting of the plate I! with the rotating ring l3, thus imparting slight rotary movement to the plate l1 and automatically setting into operation the energizing means 22, 23, 26 to eflect servo action. 'As soon as the brake is vehicle bers into contact with the others to produce brake application, auxiliary means for actuating said members into brake relation, comprising a pair of discs having camming surfaces, anti-friction elements between said discs, means for rotating one disc relative to the other, and independent energizing means for producing servo action upon brake application during movement of the vehicle, one of the discs of the auxiliary actuating means being formed with a transverse groove arranged tangent to an arc about the axis of the brake and providing, op-

released, the spring means 21 withdraws the plate I! to normal position, returning also the rolling means 44 to the base of th groove 31'.

An important factor in this brake construction is the arrangement of the disc 31, which its groove disposed in such position that, when the brake is operated during movement of the vehicle and the plate I! is slightly rotated by its contact with the rotary member l3, the balls 44 will move slightly longitudinally of the groove 31' to accommodate for the relative movement of the parts. The use of the rolling members 44 for camming purposes materially reduces the friction of the camming instrumentalities.

While the specific details of construction have been herein shown and described, the invention is not confinedthereto as alterations may be made without departing from the spiritthereof as defined by the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. Brake mechanism for vehicles'of the class described comprising in combination, a support, a plurality of braking members mounted thereon, primary means operable directly upon one of said braking members for shifting the same into contact withthe others to produce brake application, auxiliary means for actuatingsaid last-mentioned braking member into brake relation comprising a pair of discs having camming surfaces, anti-friction elements between Q said discs, one of said discs being rotatably -mounted upon the support and the other disc being fixedly mounted on the said braking member, and means for rotating one disc relative to the other, and independent energizingmeans for producing servo action-upon brake application during movement of the vehicle.

2. Brake mechanism for vehicles of th class described comprising in combination, a support,

a plurality of braking members mounted thereon, primary means for shifting one of said members into contact with the others to produce brake application, auxiliary means for actuating said members into brake relation comprising a pair of discs having camming surfaces, antifriction elements between said discs, means for rotating one disc relative to the other, and independent energizing means for producing servo action upon brake application during movement of the vehicle, said anti-friction elements of the auxiliary actuating means comprising a pair of rolling members seated in conical recesses in one I of said discs to coact with the camming surfaces of the other disc. p

3. Brake mechanism for vehicles of the class described comprising in combination, a support,

a plurality ofbraking' members mounted thereon, primary means, for shifting one of said memrotary member to be braked in said housing,

a slightly rotatable pressure plate at one side of said rotary member, primary means for actuatingsaid pressure plate into frictional contact with said rotary member, torque-actuatedmeans between the housing and the pressure plate for producing additional pressure of the plate against the rotary member upon rotativemovement of the pressure plate, and auxiliary means for urging said plate into contact with the rotary member to be braked comprising a pair of cooperative discs between the pressure plate and the housing and having their axes displaced to one side of the axis of the pressure plate, said discs having camming surfaceson "their surfaces facing each other, anti-friction mg each other, anti-friction membersbetween' members between said discs, one of said discs being fixed and the other rotatable, and means for rotating the rotary disc to shift the antifriction members about the axes of said discs to produce a camming action -urging the pressure plate into frictional contact with the rotary member to be braked.

5. Brake mechanism of the class described comprising in combination, a brake housing, a rotary member to be braked in said housing, a slightly rotatable pressure plate at one side of said rotary member, primary means for actuat ing said pressure plate into frictional contact with said rotary member, torque-actuated means betweenthe housing and the pressure plate for producing additional pressure. of the plate against the rotary member upon rotative movement of the pressure plate, and auxiliary means for urging said plate into contact with the rotary member to be braked'comprising a pair-of cooperative discs between the pressure plate and the housing and having their axes displaced to one side of the axis of the pressure plate, said discs having camming surfaces on their surfaces facsaid jdiscs, one of said discs being fixed and the other rotatable, and means for rotating the rotary disc to'shift the anti-friction members ming action urging the pressure plate into frictional contact with the rotary member to be braked, combined with an adjustable brake disc mounted in the entrance to the housing to receive the braking stresses of the rotary member and pressure plate.

6. In a disc brake of the class described, the

combination of supporting means, relatively stationary and axially shiftable braking discs thereon, and means for actuating the shiftable discs comprising a pair of camming discs having their axes displaced to one side of the first-mentioned discs, one of the camming discs being fixed and having a groove providing opposing inclined faces, and th other being rotatable and having conical recesses in its face next, the grooved race of the first-mentioned cumming disc, balls seated in the recesses between the camming discs and at opposite sides of their axes, and means for rotating the rotatable camming disc to shift the balls about the axes of said discs to cause them to ride up the inclined surfaces and produce braking action between the stationary and axially shiftabie discs.

HOMER T. LAIWBERT. 

